Method for separating waxy and oily materials



April 6, 1954 D. A. HERMANsoN 2,674,564

METHOD FOR SEPARATING WAXY AND OILY MATERIALS Filed 0G12. 12, 1951 2Sheets-Sheet l April 6, 1954 D. A. HERMANsoN METHOD FOR SEPARATING WAXYAND OILY MATERIALS Filed OCT.. l2, .1951

2 Sheets-Sheet. 2

INVENTOR. 17am/IE f/erffmfzsa BY Qa a.

L #l OR/VEY Patented Apr. 6, 1954 METHOD FOR SEPARATING AND OILYMATERIALS Donald A. Hermanson, r1aini1,N. J.,

assignor to Socony-Vacuum Oil Company, Incorporated, a corporation ofNew York` Application october 12, 1951, serial No. 251,109

This application is a continuation-impart. of my application SerialNumber 32,017, filed in the United States Patent Oflice June 9, 1948.

This invention relates to a process for the separation of wax and-oilyconstituents present in a wax bearing hydrocarbon stock and moreparticularly to a process for deoiling waxy petroleum fractions such asslack wax and the like.

The present process is broadly applicable to the problem of separatingwax and/or petrolaturn and the like from hydrocarbon oils insubstantially oil free form. The present process is particularlydirectedv to the deoiling of crystalizable wax present in highwaxystockssuch as in slack wax. y 1

A process commonly employed heretofore for thedeoiling of wax is thewell known sweating process wherein the slack wax is chilled in-.pans tocause congealing of the wax after which the mass is slowly heated toeffect sweating out of the liquid oil. The efciency of this process islow as compared with other methods from the standpoint of wax yields.Moreover, the process is conducted batchwise and requires a considerablelength of time and delicate temperature control during the heatingperiod.

Another process employed is the solvent deoiling process in which theslack waxis mixed with a suitable solvent such as propane orbenzolacetone, for example, and then chilled and ltered. l

Still another process currently employed is the emulsion deoilingprocess in which the slack wax is mixed with a non viscous non-solventwhile in molten state after which it is cooled to congeal the wax. Thenthe congealed wax is separated from the oil in non-solvent emulsion bymeans of a basket type centrifuge lined with a lter material. Suchprocesses involve extensive wax recycle to provide satisfactory yieldsof wax with low oil content.

It has also been customary in the Vprior lart to employ iilter aids suchas diatomaceous earth in powdered form to act 'as-an aid inthe dewaxingof oils by the filtration of the wax from the liquid oil. In such aprocess the liquid oil from which most of the wax has been crystallizedis withdrawn free'of the filter aid and the waxy material. The processhas not been found practicable as a method-of deoiling-waxes to obtainoil free wax. As a matter of fact, the waxy material left behind withthe filter aid is generally known as slack wax and contains substantialamounts of oil. -f wIrrUnited States Patent 1,278,023, dated Sep-- 11cleans. (c1. maiis) tember'3, 1918, there is disclosed a process fordewaxing of oils wherein the waxy oil stock is wholly absorbed by asolid porous material such as fullers earth after which the fullersearth is chilled to effect congealing of the sorbed wax. The fullersearth is then treated with a suitable oil solvent whereby the liquid oilis removed leaving behind the Wax within the pores of the adsorbent, Thewax is subsequently separated from the solid adsorbent. This process isunsatisfactory-because of the diiculty in obtaining satisfactory waxyields and the diculty of removing the wax from within the pores of theadsorbent` without use of a second solvent for the wax. V I

A major object of this invention is the pro vision of a new, improvedand economical process for the separation of wax and liquid oils whichovercomes many of the disadvantages of the prior art processes.

A specific object is the provision of a novel continuous process for thedeoiling of slack wax bymeans of porous solid adsorbent materials.

These and other objects of this invention will become apparent from thefollowing description of the invention.

There is disclosed in United States application Serial Number 31,948,led June 9, 1948, a process wherein the waxy stock such a slack wax isbrought into intimate contact with a suitable particle form solidadsorbent material under temperature conditions at which the waxconstituentsof the wax bearing oil are congealed and become and remainco-ated on the outer surface of the adsorbent particles while thenoncongealedliquid oil constituents are sorbed into the pores of theadsorbent. Thereafter the wax is removed from the surface of theadsorbent leaving behind the adsorbent bearing in its pores the liquidoil. The oil may be subsequently sep arated from the adsorbent by any ofa number of different methods. In order to obtain the optimum yields o-fwax, it is highly important in that process that the temperature becontrolled such `that the waxy constituents in the waxy stock are in acongealed or crystallized state either prior to, or substantiallyimmediately after being brought into contact with the solid adsorbentparticles or are congealed substantially simultaneously upon lbeingcontacted with the adsorbent.A Also, the waxy constituents aremaintained in congealed condition at least until the step of Wax removalfrom the adsorbent.

The present invention is directed to an improved' ,method forcontinuously Vconducting` one form of the above described wax-oilseparation process on a commercial scale. In a preferred form of thepresent invention the adsorbent particles are passed continuouslythrough a rst region wherein the waxy stock is contacted while it is inliquid form. Conditions of the contacting are preferably controlled sothat in eflect a lm of liquid waxy stock surrounds each adsorbentparticle to a thickness of less than about 0.1 inch. Coated particlesare substantially irnmediately cooled at least in part by dropping themthrough a body of a suitable cooling liquid in which the constituents ofthe waxy stock are insoluble, thereby causing the waxy constituents tocongeal on the surface of the adsorbent particles. rThe adsorbent isthen permitted to remain at the wax congealing temperature levels untilthe oily constituents of the waxy stock become sorbed into the adsorbentpores leaving the congealed waxy constituents on the surface thereof.The waxy constituents are then removed from the surface of the adsorbentby suitable means such as by melting or by physical means and the oilyconstituents may be later separately removed by suitable methods.

It will be readily understood by those skilled in the art that suchexpressions as congealed wax constituents and non-congealed liquid oilconstituents and the like as used in describing and claiming thisinvention do not necessarily mean pure oil-free wax or pure wax-free oilsince the amount of wax which will congeal from a wax-oil mixture is tosome extent dependent upon the temperature of the mixture. For example,if the mixture were cooled to 90 F. some waxy constituents might congealbut in the non-congealed liquid oil there very probably will be presentin non-congealed state some material which chemically should beclassified as a wax. For the purposes of describing and claiming thisinvention a wax which is free of oil shall be taken as meaning one inwhich the oil content is zero as determined by the S. T. M. method fordetermining oil contents of waxy stocks, A. S. T. M. Test NumberD721-43T.

The invention may be more readily understood by reference to thedrawings attached hereto in which Figure 1 is an elevational flow plan,partially in section of a preferred form of the invention and Figure 2is an elevational view,

partially in section, of a modified form of a portion of the system inFigure l. Both of these drawings are highly diagrammatic in form.

Turning now to Figure l for a description of the apparatus and itsoperation, a waxy stock such as slack wax is pumped by pump l0 through aheater or heat exchanger I I wherein it is heated to a temperatureslightly above that at which the waxy constituents begin to congeal. Theheated slack wax then passes via pipe I3 into the upper section of theelongated vertical vessel I4. A column of the molten slack wax ismaintained within section A of the coating tower IA. A column of wateror other suitable cooling liquid is maintained within a lower section oftower I4. This liquid should be of greater density than the slack waxand a non-solvent as to both wax and oil. The water in that portion ofthe tower I4 just below the slack wax column is maintained at atemperature sufficiently high to avoid congealing of wax at theinterface between the slack wax and water column. This is accomplishedby circulating water through pipe Il into and through heat exchanger I8and back into the water column via pipe IS just below the interface.Cold water enters the water column via pipe 20 below the level of warmwater outlet pipe I'I. Particle form porous adsorbent material which maypreferably be of spherical form enters the tower i4 via pipe 2i at aboutthe same temperature as the slack wax or at a somewhat lowertemperature. In general, the inlet temperature of the adsorbent shouldusually be below about 100 F. and preferably below about F. The rate ofintroduction of adsorbent is controlled by adjustment of the height ofthe outlet end of pipe 2| from conical spreader 22 and by rotation ofspreader 22. The spreader is rotated by means of gears 23, shaft 2d andmotor 40. Upright conical bafies 25 and 26 supported by rods 2l and 2Bare properly positioned below the spreader 22 in such a manner as todistribute the particles of adsorbent uniformly over the entire crosssection of the tower lf3. The adsorbent particles drop downwardlythrough the column of slack wax and become coated on their surface witha film of slack wax. The particles then drop into the water column andthe cool water acts to congeal the wax constituents on the surface ofthe particles. When the difference between the particle density andcooling liquid is small, it is desirable to add some substance such aspotassium oleate, potassium stearate, diethanol amine, sodium wax phenolsulfonate, etc. to the water or other cooling liquid to lower theinterfacial tension at the water-slack-wax interface. This will preventhold up of adsorbent particles at this interface. The particles ofadsorbent bearing the congealed material are washed by the water fromthe bottom of tower It through the curved pipe 29 onto a moving screenbelt drainer 3U. The pipe 29 is provided with a vent 3I to break thesiphon effect, and the leve1 of the highest point along pipe 29 is suchas to maintain the surface of the wax column substantially constant asindicated in the drawing, the water introduced into tower I4 via pipe Zlbeing equal in volume to that passing from the tower through pipe 29.

The screen 3l] is of a continuous belt type, moving over rollers 32 and33, one of which is driven by motor 34. The screen is encased insuitable housing 55. A pan 35 positioned under the screen catches thewater which is withdrawn via ypipe 3S to accumulator (i I. The water ispassed from accumulator 6| via pipe 62, pump 63 and pipe 29 back to thetower I4. Make up cooling water is added to the accumulator 5I via pipe6d. The adsorbent particles bearing the congealed waxy material areretained by the screen and discharged into conveyor 3l. The adsorbent isdischarged from the conveyor into one of the sorption tanks 38 and 38',these tanks being several in number although only two are shown andbeing employed in cycle. When one of the tanks 38 is lled, the adsorbentis permitted to stand therein while the temperature is controlled bymeans of heat transfer tubes (not shown) at a level at which the waxconstituents of the slack wax will remain congealed. A suitable coolingfluid may be supplied to the heat transfer tubes within each of thetanks 32! via pipe 4I and withdrawn via pipe 42. The adsorbent isretained within the tank 38 or 38 until substantially all of thenon-congealed liquid oil constituents of the slack wax are sorbed fromthe congealed mass on the surface of the particles into the pores of theparticles leaving substantially only the waxy constituents coated on theouter surface of the adsorbent particles. The adsorbent is thenwithurawnfthroughoutlets scendevano conveyed by screw conveyors 43 and44 into the upper section of the wax melting tower 45 which ismaintained substantially lled with a column of hot water. The adsorbentparticles drop throughthe column of hot water in a-zig zag path providedby baiiies 48 so that the wax depositedvon the surface of the particlesis melted'oiifV from the particles and is passed from the upper sectionof tower 45 via pipe 48 to the wax separator 49. The molten wax iswithdrawn from the upper section of separator 49 via pipe 50 Vand theseparated water is returned via pipe 109;" pump 5l and pipe 52 to thelower sectionfof the waxmelting tower 45. The water is maintained*substanl tially above the melting point of "thewax by means or" theheating coil 53 within'separator 49. The adsorbent particles 'whichstill retain the liquid oil within theA pores of the particles arecarried from the bottom of tower 45 in a water stream Via conduit 54 anddischarged' onto the moving belt screen drainer 66 'which is similar tothe screen 38 described hereinabove. The highest level of conduit 54 issuch as to permit maintaining tower 45 substantially lled with'liquid.The hot water passing through the screen 66 is eollected in pan lil andreturned via pipe 68 and pump b9 to the separator 49. Hot water make upis added to the system via pipe lll. The iiltered adsorbent materialpasses from the end of moving screen 68 via duct 'Il into one of severaloil removal tanks 'l2 and l2 (only two being shown). These tanks areused in cycle, the empty tank being opened to the duct 'l l. When one ofthe tanks l2 has become lilled to the desired level with adsorbent, itisclosed off from duct l l, as'by stopping the rotation of the star valve'I4 or 14', and a suitable oil solvent is introduced via conduit or linto the tank 12 or 12 and passed through the adsorbent mass until allthe sorbed oil is removed. The solvent bearing removed oil is withdrawnfrom tank 'I2 via pipe y16 and the oil and solvent may then be separatedin suitable equipment which is conventional in the art for that purpose.The solvent employed may be a hea-ted naphtha fraction, benzol, hexane,butyl alcohols, ethyl carbonate and acetone or other suitable oilsol-vents. After removal of the oil, the adsorbent is drained and thenpurged free of solvent by means of steam, ue gas or other suitable purgerluid entering via pipe 19. The purge uid is withdrawn from tank l2viapipe 16. IIhe reclaimed adsorbent is then discharged from tank viapipe 88 and may be reused in the deoiling process.

After long periods of continued reuse a deposit ci carbonaceous materialmay accumulate on the adsorbent which is not removed in the reclaimingsteps. Inasmuch as this material may eventually plug up the pores of theadsorbent and decrease its eiciency in the present process, thecarbonaceous contaminant should be periodically removed from theadsorbent either by means of suitable solvents or by means of burningwith air at elevated temperatures in a manner well known to thoseskilled in the art.

It will be readily understood that this invention is not limited to theparticular details of apparatus arrangement or process step techniqueshown in Figure l. For example, a number of methods may be employed foraccomplishing the initial coating of the surface of the adsorbent withthe waxy stock. An alternative method is shown in Figure 2 in which isshown an apparatus arrangement which may be :substituted-for thecoatingtower I 4 in the system ofFig'ur'e-i. i?! InrFlkuriZ, there is shown aconiinedelc'mga'tedv chamberv which may be suppliedwith'cold'waterithrough pipe 88 so `as to maintain al column 188.01 -cold watertherein. The water is continuously Withdrawn from the upper section ofvesselvia pipe 81 so as to permit continuous 'circulation of -the waterthrough column 88. An adsorbent supply hopper 89 supplied with adsorbentviav pipe 9U is positioned above chamber 85. Aieed pipe; 94 extendsvertically downward from hopper 89 into chamber 85 and terminates asubstantial distance below the surface level of thewater 'column inchamber 85 but preferably within the-upper section of the water column.A slack wax-supply hopper S2 is also positioned above thechamber 85l anda pipe 93 extends downwardly from hopper 92 to connect into feed pipe 94a short distance above the surface level of the water column 88. Slackwax is heated in heater l I0 and supplied to hopper 92 in moltencondition. It then flows via pipe 923 into pipe 94 where it mixes withadsorbent from hopper 89 at a temperature only slightly above thecongealing temperature of the Wax'constituents of the slack wax charge.The liquid charge stock fills in the void spaces between the stream ofsolid particles flowing in pipe 94 and solidies as the stream reachesthe column of cool water 88. lIf desired, the congealing of the wax maybe aided vby supplying the adsorbent from hopperi89fat av temperaturesomewhat below that required to congeal the wax constituents of themolten 'slack wax charge. Due to the head of adsorbent in pipe 94 abovethe solidified mass nearA its outlet,l a rod or ribbon of adsorbentencased `in rsolidified waxy charge stock is extruded from-the lower endof pipe 94 into the water column. 'I'he extrusion may be aided, ifdesired, by a mechanically agitated rod or other suitable device I Ilwithin the lpipe 94 which may be operated from anexternal location abovethe hopper 89. The-rod or ribbon of extruded material drops through thecolumn of .cooling water 88 and becomes'further cooled so 'as tocomplete the congealing of thewaxy constituents throughout the crosssection of the ribbon. The extruded ribbon may be caused to break up tosome extent into chunks of solidied charging stock encasing adsorbentparticles as it r`falls through the water column 88 and the material isremoved from the lower sectionV of `the chamber 85 by means of thecontinuous bucket conveyor 99 which connects into chamber 85.. Thebuckets 198 of this conveyor may be perforated so as to permit drainingof liquid from the mass of adsorbent particles encasedin cong'ealed waxystock once the buckets rise above the surface level of column B8. Ifdesired, the adsorbent may be further drained free of water by deliveryfrom conveyor 99 into the drainer 55 'shown in Figure 1. In manyoperations adequated'raining may be accomplished as the material iselevated in conveyor 99 and the adsorbent may be conveyed directly tothe adsorption tanks 38 and 38 shown in Figure 1.

When the method described in Figure 2 is ernployed, the pipe 94 shouldpreferably be subdivided near its lower end by means of verticalpartitions so as to form a number of vertical passages having a maximumhorizontal average diameter of about one half inch in diameter. 'I'hediameter of the ribbons is thereby limited to a size which will permitrapid transfer of heat into the center of the ribbons so as toaccomplishquick congealing of the wax throughout the ribbon c'rosssection. In general, the pipe 94 should extend about 0.5 to 10 inchesbelow the surface of water column88 depending on the water temperature,and being less the lower the water temperature and higher the congealingtemperature of the waxy constituents. The waxy stock should enter thepipe 94 about 0.5 to 24 inches above the surface of water column 88.

It will be readily understood that apparatus and methods other than thatshown in Figure 1 may be employed to accomplish the transfer ofmaterials between vessels, the adsorption step and the draining and waxmelting and oil recovery steps. Moreover, the removal of wax from thesurface of the adsorbent particles may be accomplished by methods otherthan by the melting of the wax. For example, the wax may be removed fromthe particles while in solid form by mechanical attrition. This lattermethod is particularly applicable when the wax is of brittle texture andwhere the adsorbent particles are spherical in form. One method foraccomplishing the mechanical separation is to rotate the adsorbentparticles in a closed drum for a period of time to crack off the brittlewax. The particles of wax may then be separated from the adsorbentparticles by elutriation, i. e. suspension in a stream of gas the flowrate of which is controlled to carry off the wax particles withoutentraining the adsorbent.

The step of removing the oil from the pores of the adsorbent particlesmay be accomplished by methods other than those employing oil solvents.For example, the adsorbent may be heated and steamed to remove the oil.

A wide variety of porous adsorbent materials may be employed in theprocess of this invention. For example, bauxites, fullers earth,activated charcoal, synthetic silica-alumina or silica and alumina gelcatalysts and other materials of similar porosity. Certain poroussorptive silica glasses such as are described in United States Patent2,106,744, issued February l, 1938, to Hood et al. may be employed, Ingeneral, the pore size of the adsorbent material should be adapted toeiect rapid sorption thereinto of the oily constituents of the waxycharge stock. The adsorbent particles should be of substantial size asdistinguished from powdered adsorbents. When powdered adsorbents of sizeless than about 100 mesh Tyler are employed the waxy constituents tendto be sorbed into the pores along with the oily material before completecongealing of the waxy constituents can be accomplished therebypreventing the desired separation. In general, it has been found thatthe adsorbent particles should be broadly at least about 0.01 inchaverage diameter and preferably at least about 0.022 inch and less thanabout 0.5 inch average diameter. A preferred adsorbent is a syntheticsilica-alumina gel catalyst in spherical form prepared in the mannerdescribed in United States Patent 2,384,946, issued September 18, 1945,to Milton M. Marisic. Y

In conducting the methods described in connection with Figures l and 2,the temperature of the waxy stock as brought into initial contact withthe adsorbent should preferably be only several degrees above that atwhich the waxy constituents will commence to congeal. The temperature ofthe cooling fluid employed to cause the congealing of wax constituentsand to maintain them congealed during the sorption period will of coursevary somewhat depending on the melting point of the waxy constituentsinvolved. For many operations, a cooling water temperature of about '70F. has been found satisfactory. The operation should be conducted so asto effect congealing of the waxy constituents as soon as possible afterthe initial contacting with the adsorbbent. The waxy constituents shouldbe congealed at least within about 10 minutes of the initial contactingand preferably within about less than one minute thereof.

The ratio of adsorbent to waxy charge stock employed in the process ofthis invention will depend to some extent upon the oil sorption capacityof the adsorbent, the percentage of oil present in the waxy stock andother operating variables. In general, for synthetic gel catalysts theratio should be of the order of 0.5 to 10 pounds of adsorbent per poundof waxy stock. In any case, suiiicient adsorbent should be employed toSorb substantially all of the oily constituents in the waxy charge.

The length of time to be devoted to the sorption period during whichnon-congealed liquid constituents are sorbed into the pores of theadsorbent will vary depending upon the thickness of the waxy stockcoating cn the adsorbent particles and upon the particular adsorbentinvolved and the viscosity and molecular size of the oily constituentsunder the sorption temperature conditions required to maintain the waxyconstituents in a congealed state. In general, it has been found thatwith adsorbent particles of about 0.09 to 0.19 inch diameter and havinga porosity similar to a synthetic silica-alumina gel catalyst, thelength of the sorption period should be at least about 0.1 hour andshould preferably be of the order of about 1 to 24 hours.

In general, the average thickness of the waxy stock coating around eachadsorbent particle should be less than about 0.1 inch and preferablyless than about 0.05 inch. In the method disclosed in Figure 1, the waxcoating is limited below 0.1 inch thickness by proper control oi' thetemperature of the adsorbent and waxy stock. In the method of Figure 2,the effective coating thickness is controlled by proper control of thewaxy stock to adsorbent feed ratio to the ribbon forming zone.

As an example of the process of this invention, the deoilng of .a waxystock by the general method shown in Figure 1 may be considered. Thewaxy charge stock was a parafnic petroleum stock having a melting pointof 116.9 F. as determined by the test procedure recommended by theAmerican Society for Testing Materials, Test. Number A. S. T. M. D87-42and an oil content of 19.2 as determined by A. S. T. M. tentative TestNumber D721-43T. The adsorbent employed was a synthetic silica-aluminagel bead catalyst prepared by the method described in United StatesPatent 2,384,946, dated September 18, 1945. The catalyst had a bulkdensity of about .74 as determined by pouring the catalyst into ameasured container and weighing. The individual particle density wasabout 1.15. The catalyst particle size was about 0.09 to 0.19 inchdiameter. The catalyst beads were dropped through a column of moltenwaxy stock one inch in depth and maintained at about 126 to 133 F. Theweight ratio of catalyst to waxy stock charge was about 3.5 to l. Thecatalyst beads bearing a coating of waxy stock then dropped through acolumn of cooling water maintained at about 70 F. About 0.3-0.5%potassium oleate was added to the water t0 redluce the interfacialtension at the water wax interface. The catalyst bearing the congealedcoating of waxy stock was permitted to stand for about 4 hours at aboutF. after which the wax was removed by attrition from the surface of theparticles. The

recovered wax had a melting point of 1353" F. and an oil content of 3.2%by weight and the yield of recovered wax amounted to 58% by weight basedon the waxy stock charge or 72% by weight of the wax present in thecharge as determined by A. S. T. M. Test Method D-72l- 43'1. By Way ofcomparison, the yield of wax obtained by the method described aboveusing a minimum cooling water temperature of 70 F. amounted to 83% byweight of the yield of wax obtained by solvent deoiling the same waxystock employing benzol-methyl ethyl ketone as the solvent at atemperature of Zero degrees F. The wax obtained by the solvent deoilingprocess contained 2.4% by weight oil.

In another experiment employing the same conditions, outlined aboveexcept that the sorption period was increased from` 4 to 20 hours, afinal wax product containing only 1.4 oil was obtained but the wax yieldbased on the charge was somewhat lower.

In still another experiment conducted similarly to the one firstdescribed, the sorpt-ion period was increased from 4 to 20 hours and theadsorbent to oil charge ratio was decreased from 3.5 to about 1.4. Thewax yield was increased to 61% by weight of the original waxy charge butthe oil content in the recovered wax increased to about 6.7% of the wax.

In another experiment conducted according to the method described inconnection with Figure 2, a waxy charge stock having a melting point ofll3.5 F. and an oil content of 20.3% oil by weight was.` deoiledemploying the same adsorbent. Referring to Figure 2, the adsorbent feedpipe @d measured one half inch` internal diameter and molten chargeentered the pipe 96 about oneV inch above the surface of water column88. The one half inch rod extruded from pipe Bil dropped into a coldwater bath maintained at about '70 F. The adsorbent to waxy charge stockweight ratio was about 1.8 to 1.0. The extruded material was permittedto stand at 80 F. for 3 hours after which the wax was removed byattrition in a ball mill. The wax yield amounted to 68% of the waxpresent in the charge stock as determined by A. S. T. M. tentative testNumber D-721-43'I and the wax product contained 4.3% oil and had amelting point of 123.3 F.

It should be understood that the.l specific details of operation and ofapparatus arrangement and the specific modifications of this inventiongiven hereinabove are intended as exemplary and the invention is not tobei construed as being limited thereto or otherwise limited eXcep-t aslimited by the following claims.

I claim:

l. The method for separating wax and oily constituents present in waxyhydrocarbon stocks which comprises, continuously passing particles of asuitable solid adsorbent of at least 0.01 inch average diameter intocontact with said waxy stock existing in the liquid phase in acontacting region, withdrawing the contacted adsorbent particles withwaxy stock on the surface thereof from said contacting region before anysubstantial amount of the wax constituents are sorbed into the pores ofthe adsorbent particles and substantially immediately dropping theparticles downwardly through a body of a suitable cooling liquid inwhich the constituents of the waxy stock are insoluble to effectcongealing of the waxy constituents on the surface of the adsorbentparticles, withdrawing the chilled adsorbent from said body of liquidand then maintaining the coated particles under conditions in whichsaid'waxy constituents remain in congealed condition in a separateregion until substantially all of the non-congealed liquid constituentsof said waxy stock are sorbed into the pores of said particles, leavingthe congealed waxy constituents on the surface of said particles andthereafter effecting removal of the waxy constituents from the surfaceof said adsorbent particles while leaving said liquid constituentswithin the pores of the adsorbent.

2. The method for separating wax and oily constituents present in waxyhydrocarbon stocks which comprises, continuously passing particles of asuitable solid adsorbent of at least 101 inch average diameter intocontact with said waxy stock existing in the liquid phase in a firstregion to effect coating of waxy stock as a liquid onto the surface ofthe particles of solid adsorbent, controlling the conditions ofcontacting so as to limit the average thickness of waxy stock coating onthe particles below about 0.1 inch, limiting the length of contact timein said first zone below that at which any substantial amount of the Waxconstituents would be sorbed into the pores of said adsorbent, thensubstantially immediately effecting congealing of the waxy constituentson the surface of said adsorbent at least partly by withdrawing thecoated adsorbent from said first region and dropping the adsorbentdownwardly through a body of a suitable cooling liquid in which theconstituents of the waxy stock are insoluble maintained in a secondregion below said first region, withdrawing the chilled adsorbent fromsaid body of liquid and then maintaining the coated particles underconditions in which said waxy constituents remain in congealed conditionin a separate region until substantially all of the non-congealed liquidconstituents of said waxy stock are sorbed into the pores of saidparticles, leaving the congealed waxy constituents on the surface ofsaid particles and thereafter effecting removal of the waxy constituentsfrom the surface of said adsorbent particles while leaving said liquidconstituents within the pores of the adsorbent.

3.l The method of claim 2 further characterized in that the coatedadsorbent is cooled in said second region within less than one minute ofthe time of the initial contact of the adsorbent with waxy stock in saidfirst region.

4. A method for deoiling wax-oil petroleum stocks which comprises:maintaining a liquid column of said wax-oil stock at a temperatureslightly above that at which the waxy constituents begin to congeal,maintaining below and contiguous with the bottom of said column ofwax-oil stock a column of Water, circulating the water in the upperportion of said column thereof through an external heater and then backinto the upper portion of said column to maintain the temperature of thewater in the upper portion of the water column near that of the wax-oilstock, introducing cold water into the intermediate portion of saidcolumn to maintain the temperature in the remainder of said water columnat a temperature at which the waxy constituents of said stock willcongeal, dropping particles of solid adsorbent comprising particles ofat least 0.01 inch average diameter downwardly through said column ofwaxoil stock to cause said particles to become coated with wax-oilstock, causing the coated particles to drop downwardly into andthroughsaid column of water to cause the .waxy constituents in the stockcoating said particles to become congealed, removing the particlesbearing the coating of wax-oil stock from `said water `co1- umn alongwith some of the cold water, and thereafter maintaining the coatedparticles at a temperature below the congealing temperature of said waxyconstituents until substantially all the non-congealed constituents ofthe wax-oil stoel; coating said particles are sorbed into the pores ofsaid adsorbent particles while leaving the waxy constituents on thesurface yof said particles, then removing the waxyfconstituents from thesurface of said particles and collecting the waxy constituentslseparately ofthe adsorbent particles and said sorbed oily'constituents.

5. A method for separating oily constituents vfrom waxy constituentspresent in a waxy hydrocarbon stock which comprises: continuouslypassing particles of asuitable solid adsorbent of at least 0.01 inchaverage diameter downwardly by gravity through a rst region whereinsaidparticles are brought into intimate `contact with said waxy stock,whereby some of the waxy stock -becomes coated around the surface 'ofeach adsorbent particle, said iirst region being maintained at atemperature at which said waxy stock is present in the liquid phase,then before the waxy constituents can -beceme sorbed into the pores ofsaid adsorbent particles, passing the adsorbent downwardly through acooling region toefiect congealing of the waxy constituentson thesurface of said particles, maintaining va b'ody of suitable coolingliquid throughout `at least a substantial portion of said cooling regionand causing the adsorbent particles to drop downwardly through saidbody, withdrawing the ladsorbent from said body of cooling liquidandmaintaining it at a temperature at which-saidf-waxy constituentsremain-congealed until-substantially all ol the oily constituents of thestock coated on the particles becomes sorbed into the -ipores of theparticles leaving the `waxy constituents on the surface thereof,thereafter effecting removal of the waxy constituents from the surfaceof said particles while leaving the non-congealed oily constituentsstill sorbed in the pores ofthe particles.

6. A method for deoiling waxoil-petroleum stocks which comprises:maintaining a liquid column of said wax-oil stock ata temperatureslightly above that at which the waxy constituents begin to congeal,dropping particles of solid adsorbent material of at least 0.01 inchaverage diameter through said column to deposit a film of said waxystock on the surface of said adsorbent particles, controlling thetemperature of the waxy stock and of the adsorbent particles ,suppliedto said column to limit the thickness of said lm on said particles belowabout 0.1 inch, substantially immediately cooling said adsorbentparticles to effect congealing of the waxy constituents of said wax-oilstock, :permitting the adsorbent particles to remain coated with saidwax-oil `stock while maintaining the waxyconstituents in a congealedstate until substantially all the noncongealed-constituents are sorbedinto-the pores of said particles, thereafter effecting removal of thewaxy constituents from the surface-of said adsorbent particles whileleaving sai-d nonccngealed liquid constituents sorbed in thepores ofsaid particles -and separately .eiecting: removal of the sorbed liquidfrom the wax free adsorbent particles.

7. A method for deoiling wax-oil petroleum stocks which comprises:maintaining a liquid column of said wax-oil stock at a temperatureslightly above that at which the waxy constituents begin to congeal,dropping particles of solid adsorbent material having an averageparticle diameter of at least 0.01 inch through said column to deposit anlm of said waxy stock on the surface of said adsorbent particles,immediately dropping said adsorbent particles bearing said film of waxystock into a bath of a suitable cooling liquid maintained at atemperature suitable for congealing the waxy constituents of saidwax-oil stock, permitting the adsorbent particles to remain coated withsaid wax-oil stock while maintaining the waxy constituents in acongealed state until substantially all the non-congealed constituentsare sorbed into the pores of said particles, thereafter eiecting removalof the waxy constituents from the surface of said adsorbent particleswhile leaving said non-congealed liquid constituents sorbed in the poresof said particles and separately effecting removal of the sorbed liquidfrom the wax freed adsorbent particles.

8. A method for deoiling waxy petroleum fractions which comprises:converging together a stream of said waxy fraction in liquid form with astream of particle form solid adsorbent material of at least 0.01 inchaverage particle diameter in a conned zone whereby the liquid waxystoel: nlls in the void spaces in the stream of adsorbent particles,chilling the resulting mixed stream to effect congealing of waxconstituents of the waxy stock and extruding a ribbon of the mixedadsorbent particles and waxy stock into a suitable bath of coolingliquid to effect further congealing of wax constituents of said waxystock, maintaining the extruded and chilled ribbon at a temperature atwhich the wax constituents will remain congealed until substantially allthe noncongealed liquid constituents of the waxy fraction are sorbedinto the pores of the adsorbent `particles while the waxy constituentsremain coated on the surface oi said particles, then removing the waxyconstituents from the surface of said particles and separately removingthe noncongealed liquid constituents from the pores of said adsorbentparticles.

9. A method for deoiling wax-oil petroleum stocks which comprises:maintaining a liquid column of said wax-oil stock at a temperatureslightly above that at which the waxy constituents begin to congeal,maintaining below and contiguous with the bottom of said column ofwax-oil stock a column of water, maintaining a short length of thecolumn of water immediately below the column of wax-oil stock at atemperature near that of the wax-oil stock and maintaining the remanderof .said column of water at a temperature at which the waxy constituentsof said stock will congeal, dropping particles of solid adsorbentcomprising particles of at least 0.01 inch average diameter downwardlythrough said column of wax-oil stock to cause said particles to becomecoated with wax-oil stock, causing the coated particles to dropdownwardly into and through said column of water to cause the waxyconstituents in the stock coating said particles to become congealed,removing the particles bearing the coating of wax-oil stock lfrom saidwater column and permitting the'particles to stand at a temperaturebelow the congealing temperature oi' said waxy constituentsuntil-subsantially all the non-congealed constituents of the Wax-oilstock coating said particles are sonbed into the pores of said adsorbentparticles while leaving the WaXy constituents on the surface of saidparticles, then removing the waxy constituents from the surface of saidparticles and collecting the waxy constituents separately oi theadsorbent particles and said sorbed oily constituents.

10. The method of claim 9 characterized in that the water in at leastthe upper portion thereof contains a suitable added material to reducethe interfacial tension at the water-waxy stock interface.

1l. A method for deoiling slack wax which comprises: forming asolidified ribbon consisting of particles of a suitable porous solidadsorbent rnaterial of greater than about 0.01 inch average diametersurrounded by the slack wax in which the waxy constituents aresubstantially crystallized, maintaining said ribbon at a temperature atwhich the Wax constituents remain solidified `for a period of at least0.1 hour until substantially all the liquid oily constituents are sorbedin the pores of said adsorbent particles leaving the crystallized wax onthe surface of said particles, then removing the wax from the surface ofsaid particles in a separate Zone while leaving the liquid oilyconstituents sorbed in the pores of said particles, iinaily separatelyremoving the oily constituents from. the pores of said particles andreusing said particles to decil additional slack Wax as aforesaid.

References Cited in the ille of this patent UNITED STATES PATENTS NumberName Date 2,537,999 Hermanson et al. Jan. 16, 1951 2,581,573 Biles et alJan. 8, 1952

1. THE METHOD OF SEPARATING WAX AND OILY CONSITITUENTS PRESENTS IN WAXYHYDROCARBON STOCKS WHICH COMPRISES, CONTINUOUSLY PASSING PARICLES OF ASUITABLE SOLID ABSORBENT OF AT LEAST 0.01 INCH AVERAGE DIAMETER INTOCONTACT WITH SAID WAXY STOCK EXISTING IN THE LIQUID PHASE IN ACONTACTING REGION, WITHDRAWING THE CONTACTED ADSORBENT PARTICLES WITHWAXY STOCK ON THE SURFACE THEREOF FROM SAID CONTACTING REGION BEFORE ANYSUBSTANTIAL AMOUNT OF THE WAX CONSTITUENTS ARE SORBED INTO THE PORES OFTHE ABSORBENT PARTICLES AND SUBSTANTIALLY IMMEDIATELY DROPPING THEPARTICLES DOWNWARDLY THROUGH A BODY OF A SUITABLE COOLING LIQUID INWHICH THE CONSTITUENTS OF THE WAXY STOCK ARE INSOLUBLE TO EFFECTCONGEALING OF THE WAXY CONSTITUENTS ON THE SURFACE OF THE ADSORBENTPARTICLES, WITHDRAWING THE CHILLED ADSORBENT FROM SAID BODY OF LIQUIDAND THEN MAINTAINING THE COATED PARTICLES UNDER CONDITIONS IN WHICH SAIDWAXY CONSTITUENTS REMAIN IN CONGEALED CONDITION IN A SEPARATE REGIONUNTIL SUBSTANTIALLY ALL OF THE NON-CONGEALED LIQUID CONSTITUENTS OF SAIDWAXY STOCK ARE SORBED INTO THE PORES OF SAID PARTICLES, LEAVING THECONGEALED WAXY CONSTITUENTS ON THE SURFACE OF SAID PARTICLES ANDTHEREAFTER EFFECTING REMOVAL OF THE WAXY CONSTITUENTS FROM THE SURFACEOF SAID ADSORBENT PARTICLES WHILE LEAVING SAID LIQUID CONSTITUENTSWITHIN THE PORES OF THE ABSORBENT.